Gas generator



May 26, 1931.

J. J. REID 1,806,823

" GAS GENERATOR 2 Sheets-Sheet 1 Filed Sept. 21, 1927 .1 llllmfllll/"IIIIIIIIIIIIIIIIIIIQ;

IN V EN TOR.

A TTORN E YS.

J. J. REID 1,806,823

GAS GENERATOR 21, 1927 2 Sheets-Sheet 2 Filed Sept.

May 26, 1931.

W .lwok. BY V mz Z rMzf ATTORNEYS.

Patented May 26, 1931 UNITED STATES PATENT OFFICE" JAMES J. REID, OF SAN FRANCISCO, CALIFORNIA GAS GENERATOR Application filed September 21, 1927. Serial No. 220,959.

' gases, such as hydrocyanic acid gas, are use Hydrocyanic acid gas fumigation for mills and the like has been in use for a great many years and at the present time it is commonly used by all progressive millers against the Mediterranean flour moth and other similar moths. It is also used to destroy flour beetles, grain weevils, etc., which infest stored food products such as flour, grain,

breakfast foods, and the like. When usedin sufiiciently strong doses, it is also effective against roaches, rats, mice and otherrodents and is particularly adapted to rid ships of these latter vermin.

My hydrocyanic gas fumigation process has many advantages over other methods now commonly practiced. Particular among these advantages is the fact that the gas is non inflammable, which means that the danger of fire by its use is removed, it will not injure cereals or other dried products stored for food or for seed, it is lighter than air and therefore will not accumulate in cellars and basements and thereby form a menace to human life as would a heavierthan-air gas.

The use of this gas, on the other hand, has some drawbacks. The greatest drawback in the use of this gas is the danger to human life. It is fatal to human life and, as a result, great care'and caution must be exercised in its use. This necessitates the employment of intelligent men for the work and where the present pot method is used several additional men are necessary to act as check on the men actually carrying out the work to take up the work should anything go wrong and also as a safety precaution.

ln fumigating according to the pot method,which method is the one most commonly used at the present time, the operator places open earthen-ware pots at various points about the space to be fumigated, the number and spacing of the pots being determined bythe cubical content of the space. He then fills each pot with a predetermined quanitiy of acid and water and places a bag of the gas-producing agent (sodium cyanide in this case) sufiicient for a charge alongside of the pots. After the pots and bags of'the gas-producing agent are properly placed, as above, the room is sealed with the exception of one' exit. The operator then starts at the pot furthest from the exit and drops the bags of gas-producing agent into the pots ofacidin rapid succession and leaves the room as quickly as possible, closing the exit behind him. It will be seen that this operation must be carried out in a hurried manner and,

as a result, no time can be lost after the first pot starts to generate gas. If anything goes wrong with one of the pots, it cannot be remedied; the operator must proceed with the remaining pots and get out of the room as quickly as possible. In carrying out this method, it is also necessary to get the sodium cyanide or other gas producing agent into the pots assoon after the acid and water are mixed as is possible and in no case should more than fifteen minutes time elapse, as it is essential to combine the sodium cyanide with the acid while it is still hot, this heat, as is well known, being generated by the chemical reaction caused when the acid and water are mixed.

From the above it will'be seen that the use j of this gas according to the above method is Very dangerous and that its results are more or less uncertain. Another difficulty in this method is that as the pots generate the gas, it will rise to the ceiling due to its heated condition and thus the hot gas will accumulate in the upper part of the room, Whereas it should be circulated while still hot throughout the room and particularly along the u a sealed tank in which the acid and water are mixed. A separate container for the gasproducing agent is located within the tank above the liquid and means are provided for discharging the contents of this container into the acid and water when it is desired to produce the fumigating gas.

For a better understanding of my invention, reference should be had to the follow ing description taken in connection with the accompanying drawings, in which- Fig. 1 is a side elevation, partly in section, of a preferred form of my apparatus.

Fig. 2 is an end view in section taken along line 22 of Fig. 1, looking in the direction of arrows.

Fig. 3 is a perspective view of the container element alone.

Fig. 1 is a side elevation, partly in section, of a modified form of my invention.

Fig. 5 shows the manner of securing the cover on the modification shown in Fig. 4;.

Fig. 6 is a plan view, partly in section, of this latter modification.

Referring now to Figs. 1 and 2 of the drawings, 1O designates a gas-tight tank having a dome or like member 11 for the generated gas. The dome 11 is provided with several outlets 12 having suitable valves 13 and lengths of hose 1 1 which can be placed to discharge the gas in any desired locality. A pressure gauge 15 is also provided, whereby the pressure of the generated gas within the tank can be determined. At one end of the tank 10, I provide a pipe 16 having a valve 17. This pipe 16 is made so as to swivel about the outer end of the valve 17. When the pipe 16 is turned up, as shown by dotted lines, it can be used when pouring the acid and water into the tank, and when turned down, as illustrated, it is used as a drain for the spent acid and residue. Vithin the tank 10 and above the normal level of the liquid, I provide a container 18 having compartments 19 so de signed and located that they will be progressively discharged as the container 18 is rotated. In order that the container 18 can be rotated freely, I provide a journal or support 20 which engages a stub shaft 21 at one end thereof. This container 18 is inserted into the tank 10 through an opening in the end located above the liquid level and a cover 22 is provided to seal this opening. The cover 22 carries a. packing gland or stuiiing box 28 through which a shaft 2 1 extends. The shaft 1: is secured to one end of the container 18 and provides a support for this end when the cover 22 is secured in place. A hand wheel 25 is mounted upon the exposed end of the shaft 2 1 and a pointer 26 is provided whereby the angular position of the container 18 is indicated. In this modification of my device, I have shown the tank 10 as mounted upon wheels by means of an axle 31 and springs 32. The dome 11 is provided with a baffle 27 which functions to prevent any acid solution from passing out of the generator and into the hose 14.

By referring to Fig. 3 of the drawings, it will be seen that the container 18 is substantially cylindrical in form and that the compartments 19 are formed by partitions 28 spaced alon its length. It will also be noted that the side walls of these compartments are cut away at different angular points so that as the container is rotated, the contents of these compartments 19 will be progressively discharged into the liquid below. In order to facilitate assembly of the container 18 upon the support 20, I provide guide rods 29 upon which the container will slide when being inserted into the tank 10 and as the pointed end of the stub shaft 21 engages the journal 20, the container will be lifted off of these guide rods where it can be freely rotated.

In Figs. 1, 5 and 6 of the drawings, I have designated parts similar to those previously described by the same numerals. The principal differences in this modification over that described, is that the contents of the container 18 are not physically discharged from the container into the liquid. In this modification the gas-producing agent is placed in a meshed form of container or basket and the tank 10 is adapted to be tilted so as to bring the liquid into contact with the gas-producing agent. A cover 33 is secured to the top of the tank by means of suitable clamps 3 1.

I shall now describe the operation of my device as used in carrying out my process of fumigation: Assuming that the room to be fumigated has been properly sealed and that the different lengths of hose 1 1 have been suitably placed therein, that the container 18 is filled with the gas-producing agent and the cover 22 secured in place, I now turn the pipe 16 into its upward position, open valve 17 and pour in a quantity of water. I next pour in all of the acid necessary and then the remainder of the water. This is all done very quickly. During this operation I also slightly open one or more of the valves 13 to prevent any back pressure which might interfere with the introduction of the acid and water and also to let off any gas which might be ge erated due to the accidental mixing of the ingredients. I then slowly turn the hand wheel 25 to discharge the con tents of the compartments 19 successively in to the acid and water as required to maintain an active generation of gas. I then open the valves 13 to a. point where the rate of discharge bears a relation to the rate of generation which will produce suiiicient pres sure to deliver the gas to the point of application. I can also control the pressure within the tank 10 by varying or regulating the rate of discharge of the container 18. In practicing my invention, I have found that a pressure in excess of one hundred and fifty pounds per square inch can be safely attained. I have also effected a considerable saving in materials over the amount necessary for the same space by the pot ethod. For instance, where formerly by the pot method I used substantially five ounces (avoirdupois) of acid and water solution to one ounce of cyanide, I cannow get better results with three ounces (avoirdupois) of acid and water solution to one ounce of cyanide. This I attribute to the fact that the cyanide is mixed with the acid and water while they are still ebullient and before the heat resulting therefrom is lost and therefore the reaction incident thereto more complete. This may be further explained by the fact that it is well known that the hotter the gas is when applied, the more effective it will be as its penetrating power is greatest when hot.

In preparing my charge I use full strength sulphuric acid 66 Baum and prefer to use the sodium cyanide in briquette form. These briquettes of cyanide, each weighing one ounce, are sold in the open market under the name of Cyanegg. A good mixture fumigating according to my process can be obtained by using ten of the above Cyanegg briquettes to fifteen ounces (avoirdupois) acid and fifteen ounces (avoirdupois) water for each one thousand cubic feet of space fumigated, in other words, by one part cyanide to three parts acid and water solution by weight.

I have found my apparatus, when practiced as above, to be very well suited to the fumigation of ships and the like, wherein a number of compartments such as state-rooms and bins, are to be fumigated. When such a problem is presented, the generator can be started and a certain pressure obtained within the tank. The operator can then go from one state-room or compartment to the next and project a certain quantity of gas into each space, the quantity of which can be determined by observing the pressure drop upon the pressure gauge at the generator, the pressure drop being a sufficiently close representation of the quantity of gas being delivered. Thus an operator can progress from one space to another in rapid succession, one operator placing the hose and a second operator at the tank opening and closing the valve 13.

Another modification of my method contemplates the use of muriatic acid instead of sulphuric acid and the addition of chlorine. When these ingredients are used a gas is produced which is much safer to handle and for some purposes it is just as effective. The

safety feature of this gas resides in its tendency to produce tears. Thus it might be termed a tear gas. With this gas, should the operator become exposed, he'will suddenly be conscious of tears and can get away before any serious damage has been done.

' In mixing this gas, I have found that a mixture of five parts chlorine, one part cyanide, and seventeen parts by weight muriatic acid produces an effective gas.

While I have shown the preferred form of my invention as now known to me, it is to be understood that various changes may be made in its construction without departing from the spirit of the invention as defined in the appended claims.

One such change which is contemplated is that the parts maybe commingled in a manner substantially reverse to the manner herein disclosed, as for instance, the acid solution might well be added successively to the sodium cyanide as distinguished from the above where it states that the sodium cyanide is progressively added to the acid solution.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. In a gas generator of the character described, a sealed tank adapted to contain a liquid, a support within said tank above said liquid, a container j ournaled to said support adapted to hold segregated quantities of a producing agent, and means for tilting said container whereby said segregated quantities of the gas producing agent can be progressively discharged from said container into said liquid to control the generation of gas.

2. In a gas generator of the character described, a sealed tank adapted to contain a liquid, a support withinsaid tank above said liquid, a container journaled to said support, compartments in said container adapted to hold a gas producing agent and adapted to be progressively discharged, and means whereby said gas producing agent can be progressively discharged from said compartments into said liquid to control the generation of gas.

3. In a gas generator of the character described, a tank adapted to contain a liquid, a support within said tank, above said liquid, a cylinder having compartments therein adapted to engage said support and hold a gas producing agent, an opening at one end 7 of said tank for the insertion of said cylinder, means for guiding one end of said cylinder into engagement with said support, a cover for sealing said opening and adapted to support the other end of said cylinder, whereby it can be rotated to progressively discharge the contents of said compartments into said liquid, and means whereby the gencrate-d gas can be withdrawn from said tank.

4. In a gas generator of the character clescribed, the combination of a sealed tank adapted to contain a gas producing ingredient, a container supported Within said tank above the ingredient therein having a plurality of compartments which are adapted to hold measured quantities of a second gas producing ingredient, means external of said tank connected with said container, whereby said second gas producing ingredient may be discharged progressively from the compartments of said container and into contact with said first gas producing ingredient, and means for controlling the Withdrawal of the gas generated in said tank as said ingredients combine.

- JAMES J. REID. 

